In the past, walls formed from building blocks, etc., have been constructed by the placement of blocks upon one another, in overlying relationship and in courses of blocks with mortar interposed between the horizontal and vertical surfaces of the blocks. The construction of walls in this manner is tedious and requires a relatively skilled mason to form the wall upright and uniformly. When the wall has been formed, it is sometimes found that the wall is out of plumb or that the wall should be changed for some reason. Moreover, the horizontal strength characteristics of conventionally formed block walls is not particularly good unless the wall is fabricated from relatively thick blocks or unless the wall is formed with additional thickness of material, such as brick.